~ Flu news, Information, Prepardness

Daily Archives: May 6, 2009

May 6 (Bloomberg) — The World Health Organization has determined that at least two influenza shots will be needed to protect against both the seasonal form of the disease and the new swine flu.

The United Nation’s health agency will ask drugmakers to start producing a vaccine for swine strain once they finish making shots for seasonal flu, (Snip) WHO is waiting to hear from Sanofi-Aventis SA, GlaxoSmithKline Plc and other vaccine manufacturers when they are ready to switch to making inoculations for the new pig- derived virus, Kieny said. The virus, formally known as A/H1N1, has spread to 20 countries since Geneva-based WHO first identified cases in Mexico and the U.S. on April 24.

“It is important to have seasonal vaccine available,” Kieny said. The health agency will ask flu-vaccine makers to produce immunizations against the swine variant even before it is certain H1N1 will re-emerge in the Northern Hemisphere’s coming winter, she said. The agency wants to make sure inoculations for seasonal flu are readily available before the companies switch to making swine flu shots.

“Come November, if this isn’t a killer virus, and we don’t have seasonal flu vaccine, we’ll be crucified,” Kieny said. She hopes a recommendation can be made “within days” to start manufacturing the swine flu shot, she said. A recommendation to stop making vaccine for the seasonal strain will depend on supplies, and may be made a few weeks later, Kieny said.

Sanofi-Aventis, the world’s largest maker of seasonal flu vaccine, said it plans to produce seasonal vaccine until August. “If we stop too fast, to produce the vaccine against the new strain, if it is decided to produce the new strain, we will have a lower amount of seasonal,” (Snip) The three main seasonal flu strains — H3N2, another form of H1N1, and type B — cause 250,000 to 500,000 deaths a year globally, according to the WHO.

The Obama administration is considering an unprecedented fall vaccination campaign that could entail giving Americans three flu shots — one to combat annual seasonal influenza and two targeted at the new swine flu virus spreading across the globe.

If enacted, the multibillion-dollar effort would represent the first time that top federal health officials have asked Americans to get more than one flu vaccine in a year, raising serious challenges concerning production, distribution and the ability to track potentially severe side effects.

Another option, said Dale Morse, chairman of the advisory committee on immunization practices at the Centers for Disease Control and Prevention, is adding to the seasonal flu shot an ingredient targeted at the new virus.
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Washington – A flu virus is a powerhouse of evolution, mutating at the maximum speed nature allows. A mild virus can morph into a killer and vice versa. One change already made this year’s swine flu more of a problem, helping it spread more easily among people. The big question is: What mutations are next? That’s why scientists are watching it so closely. “There are no rules to flu viruses; they are just so mutable,” said Dr. Paul Glezen, a flu epidemiologist at the Baylor College of Medicine in Houston. “The fact that it changes all the time really confounds our efforts to control it.”

Think of flu’s evolution like a family tree: In the current flu’s distant ancestry are last century’s three pandemics. But its more immediate relatives are swine flu strains that were no big deal to humans. The good news right now is that this flu has lost some of the most dangerous genetic traits of past pandemics. The bad news is that it’s gained something its parents didn’t have: the ability to spread from human to human.

Flu reproduces about every eight hours, said Dr. Raul Rabadan, professor of computational biology at Columbia University. That means this morning’s flu is a parent by the afternoon, a grandparent by the evening, and a great-grandparent by the next day.

Instead of complex double-helix DNA – nature’s basic biological instruction book – flu has a simpler, single strand of genetic code. Normal DNA has a spellcheck-like system that reduces mistakes in replicating the code; the flu virus does not. So mutations come more often. If the mutations are good for the virus, they multiply, and voila, you have a new and sometimes nastier flu.

Scientists are trying to piece together swine flu’s ever-changing genome, its genetic ancestors and the random mutations that in this instance turned a simple pig disease into something that scares billions. They also don’t know how the virus is going to mutate next.

HOUSTON (Reuters) – A Texas woman with the new H1N1 flu died earlier this week, state health officials said on Tuesday, the second death outside of Mexico, where the epidemic appeared to be waning. Officials said the woman, who was in her 30s, had other health problems. U.S. health officials have predicted that the swine flu virus would spread and inevitably kill some people, just as seasonal flu does. Last week a Mexican toddler visiting Texas also died.Mexican officials have reported 29 confirmed deaths.

The World Health Organization was monitoring the spread of the virus and said 21 countries have officially reported 1,490 cases. The United States has 403 confirmed cases in 38 states, the U.S. Centers for Disease Control and Prevention said, with another 700 “probable” cases. Canada has reported 165 cases.“Those numbers will go up, we anticipate, and unfortunately there are likely to be more hospitalizations and more deaths,” U.S. Health and Human Services Secretary Kathleen Sebelius said.

Health officials said the outbreak seemed to be slowing in Mexico, the country hardest-hit by the virus, which is a mixture of swine viruses and some elements of human and bird flu. At the same time, infections were breaking out globally and are expected to spread. (Snip)

PANDEMIC ALERT

The question remained how far the virus would spread and how serious would it be. The WHO remained at pandemic alert level 5, meaning a pandemic is imminent. “If it spreads around the world you will see hundreds of millions of people get infected,” the WHO’s Dr. Keiji Fukuda told a news briefing. If it continues to spread outside the Americas, the WHO would likely move to phase 6, a full pandemic alert. This would prompt countries to activate pandemic plans, distribute antiviral drugs and antibiotics and perhaps advise people to take other precautions like limiting large gatherings.

“It’s not so much the number of countries, but whether the virus sets up shop in any of those countries like it has here and starts to spread person to person. And given the number of countries that have cases, one would think that eventually that criteria would be met,” said acting CDC director Dr. Richard Besser. He and Fukuda said it would be important to watch the Southern Hemisphere, where winter and the flu season are just beginning.

Other pandemics have started with a mild new virus in spring that has come back to cause severe disease later in the year. WHO said it would begin sending 2.4 million treatment courses of Roche AG’s and Gilead Sciences Inc’s Tamiflu, an antiviral proven effective against the new flu, to 72 nations, including Mexico. Fukuda said the WHO was still trying to answer the most pressing questions, including why more people have died in Mexico than anywhere else.

How one virus spread from pigs and birds to humans around the globe. And why microbes like the H1N1 flu have become a growing threat.

Around Thanksgiving 2005 a teenage boy helped his brother-in-law butcher 31 pigs at a local Wisconsin slaughterhouse, and a week later the 17-year-old pinned down another pig while it was gutted. In the lead-up to the holidays the boy’s family bought a chicken and kept the animal in their home, out of the harsh Sheboygan autumn. On Dec. 7, the teenager came down with the flu, suffering an illness that lasted three days. He visited a local clinic, then fully recovered, and nobody else in his family took ill.

This incident would hardly seem worth mentioning except that the influenza virus that infected the Wisconsin lad was unlike any previously seen. It appeared to be a mosaic of a wild-bird form of flu, a human type and a strain found in pigs.

It was an H1N1 swine influenza. Largely ignored at the time, the Wisconsin virus was a step along the evolutionary tree, leading to a virus that four years later would stun the world.

Flash-forward to April 2009, and young Édgar Enrique Hernández in faraway La Gloria, Mexico, suffers a bout of flu, found to be caused by a similar mosaic of swine/bird/human flu, also H1N1. And thousands of miles away in Cairo, the Egyptian government decides pigs are the source of disease, and orders 300,000 animals in the predominantly Muslim (therefore not pork-consuming) society slaughtered.
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Each of these three incidents is related to the unfolding influenza crisis. It is the manner of human beings to seek blame during times of fear. Fingers are now pointing, either at the entire pig species Sus domestica, or at the nation of Mexico. Such exercises in blame are not only scientifically ill founded, but are likely to prompt government actions that, at the very least, are useless and, at worst, harmful for efforts to control a pandemic.

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A wiser set of pig-related actions would turn to the strange ecology we have created to feed meat to our massive human population. It is a strange world wherein billions of animals are concentrated into tiny spaces, breeding stock is flown to production sites all over the world and poorly paid migrant workers are exposed to infected animals. And it’s going to get much worse, as the world’s once poor populations of India and China enter the middle class. Back in 1980 the per capita meat consumption in China was about 44 pounds a year: it now tops 110 pounds. In 1983 the world consumed 152 million tons of meat a year. By 1997 consumption was up to 233 million tons. And the United Nations Food and Agriculture Organization estimates that by 2020 world consumption could top 386 million tons of pork, chicken, beef and farmed fish.

This is the ecology that, in the cases of pigs and chickens, is breeding influenza. It is an ecology that promotes viral evolution. And if we don’t do something about it, this ecology will one day spawn a severe pandemic that will dwarf that of 1918.

Evolutionary biology may sometimes seem like an arcane academic pursuit, but just try telling that to Gavin Smith, a virologist at Hong Kong University. For the past week, Dr. Smith and six other experts on influenza in Hong Kong, Arizona, California and Britain have been furiously analyzing the new swine flu to figure out how and when it evolved. The first viruses from the outbreak were isolated late last month, but Dr. Smith and his colleagues report on their Web site that the most recent common ancestor of the new viruses existed 6 to 11 months ago. “It could just have been going under the radar,” Dr. Smith said.

The current outbreak shows how complex and mysterious the evolution of viruses is. That complexity and mystery are all the more remarkable because a virus is life reduced to its essentials. A human influenza virus, for example, is a protein shell measuring about five-millionths of an inch across, with 10 genes inside. (We have about 20,000.) Some viruses use DNA, like we do, to encode their genes. Others, like the influenza virus, use single-strand RNA. But viruses all have one thing in common, said Roland Wolkowicz, a molecular virologist at San Diego State University: they all reproduce by disintegrating and then reforming.

A human flu virus, for example, latches onto a cell in the lining of the nose or throat. It manipulates a receptor on the cell so that the cell engulfs it, whereupon the virus’s genes are released from its protein shell. The host cell begins making genes and proteins that spontaneously assemble into new viruses. “No other entity out there is able to do that,” Dr. Wolkowicz said. “To me, this is what defines a virus.”

In H1N1: Why Do Schools Close, And When Do They Open?, we looked at the rationale behind early school closure. However, as the virus becomes more widespread, that rationale changes. Once it is in the community, closing individual schools makes less sense. There will already be mild cases in the schools that don’t close. For that reason, the policy will adjust to the evolving situation. This has already started in Seattle.

Despite the identification of seven new probable cases of swine flu, King County is easing its response and will no longer mandate that schools be closed.Instead, county health officials are asking that students and faculty stay home from school for at least seven days if they experience flu-like symptoms.

CDC will evaluate what to do for the rest of the country, and local and state health officials will advise the school systems:

With the virus almost everywhere, school closings will no longer have much effect. Only 35 people have been hospitalized with the virus.

For communities, this will move schools closures back towards what’s normally done. Remember, school lunches don’t get seved when the schools close.